From: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxx> This patch adds support for the Diolan DLN-2 I2C master module. Due to hardware limitations it does not support SMBUS quick commands. Information about the USB protocol interface can be found in the Programmer's Reference Manual [1], see section 6.2.2 for the I2C master module commands and responses. [1] https://www.diolan.com/downloads/dln-api-manual.pdf Signed-off-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxx> Signed-off-by: Octavian Purdila <octavian.purdila@xxxxxxxxx> --- .../ABI/testing/sysfs-bus-i2c-busses-dln2 | 5 + drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-dln2.c | 378 +++++++++++++++++++++ 4 files changed, 394 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-i2c-busses-dln2 create mode 100644 drivers/i2c/busses/i2c-dln2.c diff --git a/Documentation/ABI/testing/sysfs-bus-i2c-busses-dln2 b/Documentation/ABI/testing/sysfs-bus-i2c-busses-dln2 new file mode 100644 index 0000000..ad55af6 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-i2c-busses-dln2 @@ -0,0 +1,5 @@ +What: /sys/bus/i2c/devices/.../dln2_i2c_freq +Date: September 2014 +Contact: Octavian Purdila <octavian.purdila@xxxxxxxxx> +Description: + This attribute shows/sets the frequency (in Hz) of the I2C bus. diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 2ac87fa..6afc17e 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1021,4 +1021,14 @@ config SCx200_ACB This support is also available as a module. If so, the module will be called scx200_acb. +config I2C_DLN2 + tristate "Diolan DLN-2 USB I2C adapter" + depends on MFD_DLN2 + help + If you say yes to this option, support will be included for Diolan + DLN2, a USB to I2C interface. + + This driver can also be built as a module. If so, the module + will be called i2c-dln2. + endmenu diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 49bf07e..3118fea 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -100,5 +100,6 @@ obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o obj-$(CONFIG_I2C_PCA_ISA) += i2c-pca-isa.o obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o obj-$(CONFIG_SCx200_ACB) += scx200_acb.o +obj-$(CONFIG_I2C_DLN2) += i2c-dln2.o ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG diff --git a/drivers/i2c/busses/i2c-dln2.c b/drivers/i2c/busses/i2c-dln2.c new file mode 100644 index 0000000..15b7f35b --- /dev/null +++ b/drivers/i2c/busses/i2c-dln2.c @@ -0,0 +1,378 @@ +/* + * Driver for the Diolan DLN-2 USB-I2C adapter + * + * Copyright (c) 2014 Intel Corporation + * + * Derived from: + * i2c-diolan-u2c.c + * Copyright (c) 2010-2011 Ericsson AB + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/platform_device.h> +#include <linux/mfd/dln2.h> + +#define DLN2_I2C_MODULE_ID 0x03 +#define DLN2_I2C_CMD(cmd) DLN2_CMD(cmd, DLN2_I2C_MODULE_ID) + +/* I2C commands */ +#define DLN2_I2C_GET_PORT_COUNT DLN2_I2C_CMD(0x00) +#define DLN2_I2C_ENABLE DLN2_I2C_CMD(0x01) +#define DLN2_I2C_DISABLE DLN2_I2C_CMD(0x02) +#define DLN2_I2C_IS_ENABLED DLN2_I2C_CMD(0x03) +#define DLN2_I2C_SET_FREQUENCY DLN2_I2C_CMD(0x04) +#define DLN2_I2C_GET_FREQUENCY DLN2_I2C_CMD(0x05) +#define DLN2_I2C_WRITE DLN2_I2C_CMD(0x06) +#define DLN2_I2C_READ DLN2_I2C_CMD(0x07) +#define DLN2_I2C_SCAN_DEVICES DLN2_I2C_CMD(0x08) +#define DLN2_I2C_PULLUP_ENABLE DLN2_I2C_CMD(0x09) +#define DLN2_I2C_PULLUP_DISABLE DLN2_I2C_CMD(0x0A) +#define DLN2_I2C_PULLUP_IS_ENABLED DLN2_I2C_CMD(0x0B) +#define DLN2_I2C_TRANSFER DLN2_I2C_CMD(0x0C) +#define DLN2_I2C_SET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0D) +#define DLN2_I2C_GET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0E) +#define DLN2_I2C_GET_MIN_FREQUENCY DLN2_I2C_CMD(0x40) +#define DLN2_I2C_GET_MAX_FREQUENCY DLN2_I2C_CMD(0x41) + +#define DLN2_I2C_FREQ_STD 100000 + +#define DLN2_I2C_MAX_XFER_SIZE 256 +#define DLN2_I2C_BUF_SIZE (DLN2_I2C_MAX_XFER_SIZE + 16) + +struct dln2_i2c { + struct platform_device *pdev; + struct i2c_adapter adapter; + u32 freq; + u32 min_freq; + u32 max_freq; + u8 port; + /* + * Buffer to hold the packet for read or write transfers. One + * is enough since we can't have multiple transfers in + * parallel on the i2c adapter. + */ + void *buf; +}; + +static int dln2_i2c_enable(struct dln2_i2c *dln2, bool enable) +{ + int ret; + u16 cmd; + + if (enable) + cmd = DLN2_I2C_ENABLE; + else + cmd = DLN2_I2C_DISABLE; + + ret = dln2_transfer(dln2->pdev, cmd, &dln2->port, sizeof(dln2->port), + NULL, NULL); + if (ret < 0) + return ret; + + return 0; +} + +static int dln2_i2c_set_frequency(struct dln2_i2c *dln2, u32 freq) +{ + int ret; + struct tx_data { + u8 port; + __le32 freq; + } __packed tx; + + tx.port = dln2->port; + tx.freq = cpu_to_le32(freq); + + ret = dln2_transfer(dln2->pdev, DLN2_I2C_SET_FREQUENCY, &tx, sizeof(tx), + NULL, NULL); + if (ret < 0) + return ret; + + dln2->freq = freq; + + return 0; +} + +static int dln2_i2c_get_freq(struct dln2_i2c *dln2, u16 cmd, u32 *res) +{ + int ret; + __le32 freq; + unsigned len = sizeof(freq); + + ret = dln2_transfer(dln2->pdev, cmd, &dln2->port, sizeof(dln2->port), + &freq, &len); + if (ret < 0) + return ret; + if (len < sizeof(freq)) + return -EPROTO; + + *res = le32_to_cpu(freq); + + return 0; +} + +static int dln2_i2c_setup(struct dln2_i2c *dln2) +{ + int ret; + + ret = dln2_i2c_enable(dln2, false); + if (ret < 0) + return ret; + + ret = dln2_i2c_get_freq(dln2, DLN2_I2C_GET_MIN_FREQUENCY, + &dln2->min_freq); + if (ret < 0) + return ret; + + ret = dln2_i2c_get_freq(dln2, DLN2_I2C_GET_MAX_FREQUENCY, + &dln2->max_freq); + if (ret < 0) + return ret; + + ret = dln2_i2c_set_frequency(dln2, DLN2_I2C_FREQ_STD); + if (ret < 0) + return ret; + + ret = dln2_i2c_enable(dln2, true); + + return ret; +} + +static int dln2_i2c_write(struct dln2_i2c *dln2, u8 addr, + u8 *data, u16 data_len) +{ + int ret; + struct { + u8 port; + u8 addr; + u8 mem_addr_len; + __le32 mem_addr; + __le16 buf_len; + u8 buf[DLN2_I2C_MAX_XFER_SIZE]; + } __packed *tx = dln2->buf; + unsigned len; + + BUILD_BUG_ON(sizeof(*tx) > DLN2_I2C_BUF_SIZE); + + tx->port = dln2->port; + tx->addr = addr; + tx->mem_addr_len = 0; + tx->mem_addr = 0; + tx->buf_len = cpu_to_le16(data_len); + memcpy(tx->buf, data, data_len); + + len = sizeof(*tx) + data_len - DLN2_I2C_MAX_XFER_SIZE; + ret = dln2_transfer(dln2->pdev, DLN2_I2C_WRITE, tx, len, + NULL, NULL); + if (ret < 0) + return ret; + + return data_len; +} + +static int dln2_i2c_read(struct dln2_i2c *dln2, u16 addr, u8 *data, + u16 data_len) +{ + int ret; + struct { + u8 port; + u8 addr; + u8 mem_addr_len; + __le32 mem_addr; + __le16 buf_len; + } __packed tx; + struct { + __le16 buf_len; + u8 buf[DLN2_I2C_MAX_XFER_SIZE]; + } __packed *rx = dln2->buf; + unsigned rx_len = sizeof(*rx); + + BUILD_BUG_ON(sizeof(*rx) > DLN2_I2C_BUF_SIZE); + + tx.port = dln2->port; + tx.addr = addr; + tx.mem_addr_len = 0; + tx.mem_addr = 0; + tx.buf_len = cpu_to_le16(data_len); + + ret = dln2_transfer(dln2->pdev, DLN2_I2C_READ, &tx, sizeof(tx), + rx, &rx_len); + if (ret < 0) + return ret; + if (rx_len < sizeof(rx->buf_len) + data_len) + return -EPROTO; + if (le16_to_cpu(rx->buf_len) != data_len) + return -EPROTO; + + memcpy(data, rx->buf, data_len); + + return data_len; +} + +static int dln2_i2c_xfer(struct i2c_adapter *adapter, + struct i2c_msg *msgs, int num) +{ + struct dln2_i2c *dln2 = i2c_get_adapdata(adapter); + struct i2c_msg *pmsg; + int i; + + for (i = 0; i < num; i++) { + int ret; + + pmsg = &msgs[i]; + + if (pmsg->len > DLN2_I2C_MAX_XFER_SIZE) + return -EINVAL; + + if (pmsg->flags & I2C_M_RD) { + ret = dln2_i2c_read(dln2, pmsg->addr, pmsg->buf, + pmsg->len); + if (ret < 0) + return ret; + + pmsg->len = ret; + } else { + ret = dln2_i2c_write(dln2, pmsg->addr, pmsg->buf, + pmsg->len); + if (ret != pmsg->len) + return -EPROTO; + } + } + + return num; +} + +static u32 dln2_i2c_func(struct i2c_adapter *a) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | + I2C_FUNC_SMBUS_I2C_BLOCK; +} + +static const struct i2c_algorithm dln2_i2c_usb_algorithm = { + .master_xfer = dln2_i2c_xfer, + .functionality = dln2_i2c_func, +}; + +static ssize_t dln2_i2c_freq_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dln2_i2c *dln2 = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", dln2->freq); +} + +static ssize_t dln2_i2c_freq_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct dln2_i2c *dln2 = dev_get_drvdata(dev); + unsigned long freq; + int ret; + + if (kstrtoul(buf, 0, &freq) || freq < dln2->min_freq || + freq > dln2->max_freq) + return -EINVAL; + + ret = dln2_i2c_enable(dln2, false); + if (ret < 0) + return ret; + + ret = dln2_i2c_set_frequency(dln2, freq); + if (ret < 0) + return ret; + + ret = dln2_i2c_enable(dln2, true); + + return count; +} + +static DEVICE_ATTR_RW(dln2_i2c_freq); +static struct attribute *dln2_i2c_freq_attrs[] = { + &dev_attr_dln2_i2c_freq.attr, + NULL +}; +ATTRIBUTE_GROUPS(dln2_i2c_freq); + +static int dln2_i2c_probe(struct platform_device *pdev) +{ + int ret; + struct dln2_i2c *dln2; + struct device *dev = &pdev->dev; + struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev); + + dln2 = devm_kzalloc(dev, sizeof(*dln2), GFP_KERNEL); + if (!dln2) + return -ENOMEM; + + dln2->buf = devm_kmalloc(dev, DLN2_I2C_BUF_SIZE, GFP_KERNEL); + if (!dln2->buf) + return -ENOMEM; + + dln2->pdev = pdev; + dln2->port = pdata->port; + + /* setup i2c adapter description */ + dln2->adapter.owner = THIS_MODULE; + dln2->adapter.class = I2C_CLASS_HWMON; + dln2->adapter.algo = &dln2_i2c_usb_algorithm; + dln2->adapter.dev.parent = dev; + dln2->adapter.dev.groups = dln2_i2c_freq_groups; + i2c_set_adapdata(&dln2->adapter, dln2); + snprintf(dln2->adapter.name, sizeof(dln2->adapter.name), "%s-%s-%d", + "dln2-i2c", dev_name(pdev->dev.parent), dln2->port); + + platform_set_drvdata(pdev, dln2); + + /* initialize the i2c interface */ + ret = dln2_i2c_setup(dln2); + if (ret < 0) { + dev_err(dev, "failed to initialize adapter: %d\n", ret); + return ret; + } + + /* and finally attach to i2c layer */ + ret = i2c_add_adapter(&dln2->adapter); + if (ret < 0) { + dev_err(dev, "failed to add I2C adapter: %d\n", ret); + goto out_disable; + } + + return 0; + +out_disable: + dln2_i2c_enable(dln2, false); + + return ret; +} + +static int dln2_i2c_remove(struct platform_device *pdev) +{ + struct dln2_i2c *dln2 = platform_get_drvdata(pdev); + + i2c_del_adapter(&dln2->adapter); + dln2_i2c_enable(dln2, false); + + return 0; +} + +static struct platform_driver dln2_i2c_driver = { + .driver.name = "dln2-i2c", + .probe = dln2_i2c_probe, + .remove = dln2_i2c_remove, +}; + +module_platform_driver(dln2_i2c_driver); + +MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@xxxxxxxxx>"); +MODULE_DESCRIPTION("Driver for the Diolan DLN2 I2C master interface"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:dln2-i2c"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
